Pen



FIG. 1 is a perspective view of the front, left, and top side of a pen showing an embodiment of the new design.

FIG. 2 is a front view thereof.

FIG. 3 is a rear view thereof.

FIG. 4 is a right view thereof.

FIG. 5 is a left view thereof.

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines show portions of the article that form no part of the claimed design. 

CLAIM The ornamental design of a pen design, as shown and described. 